Semiconductor device manufacturing system for etching a semiconductor by plasma discharge

Abstract

A semiconductor device manufacturing system has a vacuum chamber which is provided with a cathode electrode for holding a substrate to be processed and into which a reactive gas for generating discharging plasma by the application of a high-frequency electric power is introduced, a measuring circuit which measures at least one of the impedance of a system including the plasma, the peak-to-peak voltage of a high-frequency signal applied to the plasma, and a self-bias voltage applied to the cathode electrode, and a sense circuit which compares the measured value from the measuring circuit with previously prepared data and senses the change of processing characteristics with time for the substrate in using the discharging plasma or the cleaning time of the inside of the vacuum chamber.

1. A semiconductor device manufacturing system comprising:
 a vacuum chamber provided with a cathode electrode for holding a substrate to be processed and into which a reactive gas for generating discharging plasma by the application of a high-frequency electric power is introduced; 
 a high-frequency power supply connected to said cathode electrode, for applying a high-frequency electric power to said cathode electrode; 
 a cooling gas carrying path provided at said cathode electrode and into which a cooling gas is introduced to cool said substrate; 
 an electronic valve provided at said cooling gas carrying path in such a manner that the pressure of said cooling gas introduced into said cooling gas carrying path is adjusted; 
 a measuring circuit connected to said cathode electrode, for measuring at least one of the impedance of a system including said plasma, the peak-to-peak voltage of a high-frequency signal applied to said plasma, and a self-bias voltage applied to said cathode electrode; and 
 a control circuit for receiving the measured value from said measuring circuit, for supplying an output based on said measured value, and for controlling the operation of said valve in such a manner that the measured value of said measuring circuit is kept at a specific value. 
 
     
     
       2. The system according to  claim 1 , wherein said reactive gas is an etching gas for etching said substrate to be processed. 
     
     
       3. The system according to  claim 1 , further comprising an impedance matching circuit provided between said high-frequency power supply and said cathode electrode of said vacuum chamber, for effecting the impedance matching between the output of said high-frequency power supply and a load on the high-frequency power supply.